Which of the changes occur in bone growth :

Ans. is 'd' Increased osteocalcin To get to the answer lets see the normal bone metabolism.Osteoblasts are the main cells of bone. They give rise to both osteocytes and osteoclasts.Osteocytes further secrete osteoid which forms the bone matrix.Osteoid is a nonmineralized bone matrix, primarily containing type I collagen. This nonmineralized bone matrix becomes mineralized by addition of calcium hydroxyapatite and calcium-phosphorus.This process of mineralization requires the presence of osteocalcin and osteonectin protein.Bone is an actively metabolizing tissue with a continuous turnover of both osteoid and mineral. Bone resorption by osteoclasts is normally balanced exactly by bone deposition of osteoblasts.Main bone cells|Osteoblasts - Osteoclasts (continuous resorption of bones)|Osteocytes|Osteoid (nonmineralized bone matrix)|Becomes mineralized by|Osteonectin & (cause the addition of calcium hydroxyapatite Osteocalcin & calcium phosphorus)Read what Robbins has to say about the role of osteocalcin "It is a noncollagenous protein of bone matrix. It is unique to the bone. It is measurable in the serum and used as a sensitive and specific marker of osteoblastic activity".